Multi-unit blood processor with rotating valves

ABSTRACT

An apparatus for separating at least two discrete volumes of a composite liquid into at least a first component and a second component, comprising a valve design that facilitates loading and unloading of blood bags and associated tubing and bag sets. The valves comprise a rotating head, mounted on a shaft, which assumes a “load” position. The head pivots to an “open” position, which secures the tube in its designated location, but which maintains an open lumen through the tube. When the head is in a “closed” position, blood components cannot flow through the tube. The valve apparatus comprises means for maintaining a constant pressure on the tube and contact with the tube as the tube is melted and sealed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/267,484 filed Dec. 8, 2009.

FIELD OF THE INVENTION

The present invention relates to an apparatus and a method forseparating at least two discrete volumes of a blood into at least twocomponents each.

BACKGROUND

U.S. Pat. No. 7,674,221 describes an apparatus for separating discretevolumes of a composite liquid such as blood into at least twocomponents.

The apparatus and a method of the invention are particularly appropriatefor the separation of biological fluids comprising an aqueous componentand one or more cellular components. Potential uses of the inventioninclude: extracting a plasma component and a cellular component(including platelets, white blood cells, and red blood cells) from avolume of whole blood. A component, such as washed red blood cells, mayalso be filtered so as to remove residual prions, white blood cells orplatelets from the red blood cells.

An apparatus for processing blood components that can process at once atleast two discrete volumes of a composite liquid, in particular, twounequal volumes wherein the proportions of the various components of thecomposite liquid that may vary from one discrete volume to another one,is known from U.S. Pat. No. 7,674,221. A method is described therein forseparating at least two discrete volumes of a composite liquid into atleast a first component and a second component. The method comprises atleast two separation bags containing two discrete volumes of a compositeliquid in separation cells mounted on a rotor; storing in at least onecontainer on the rotor at least two first component bags connected tothe at least two separation bags respectively; separating at least afirst and a second components in each of the separation bags;transferring at least one fraction of a first separated component into acomponent bag; detecting a characteristic of a component at a locationin each separation bag; and stopping transferring the fraction of thefirst component upon detection of the characteristic of a component atthe first determined location.

SUMMARY OF THE INVENTION

The present invention comprises improvements on a centrifugal bloodseparation device capable of processing a plurality of blood units atthe same time. The improvements include a valve design that facilitatesloading and unloading of blood bags and associated tubing and bag sets.The valves of this invention comprise a rotating head, mounted on ashaft, which assumes a “load” position that allows a tube of thedisposable set to be rapidly and securely inserted into a designatedlocation on the rotor. The head pivots to an “open” position, whichsecures the tube in its designated location, but which maintains an openlumen through the tube, whereby blood or a blood component can flowthrough the tube. The head may also be drawn into a “closed” positionfrom time to time. When the head is in the closed position, blood orblood components cannot flow through the tube. The head may also conveyradio frequency energy to the tube to seal and sever the tube. The valveapparatus comprises means for maintaining a constant pressure on thetube and contact with the tube as the tube is melted and sealed. Theconstant pressure means may comprise a pre-loaded spring or similarstructure, such as a pre-loaded pneumatic actuator. The valve maymechanically and electrically disconnect the shaft and head from astepper motor during radiofrequency (RF) welding that seals the tube.

In addition, an asymmetrical junction in the blood bag and tubing setinhibits errors when the bags and tubings are loaded into the device.Further, a well is provided on a rotor near the axis of rotation forreceiving a relatively rare blood component, such as mesenchymal stemcells (MSC) or another component, or for receiving a fluid that can beused multiple times, such as a washing solution. The well is positionedsuch that the processing bag is located in a relatively high forceregion of the centrifugal field produced by the rotation of the rotor,while the component bags are located in a lower force region, and asmall bag placed in the well would be in the lowest force region. Byreason of bag placement in high, intermediate and low force regions ofthe centrifugal field, air will tend to collect in the small bag in thewell. Moreover, a shorter line or tube can be used to connect the smallbag to the entire bag assembly. The three placement zones aides insimplifying the bag assembly and makes the process of loading the bagassembly into the rotor easier.

According to the present invention, an apparatus is provided forseparating at least two discrete volumes of a composite liquid into atleast a first component and a second component, the apparatus comprisinga centrifuge having a rotor with a rotation axis, at least twoseparation cells mounted on the rotor, each cell adapted to receive aseparation bag containing a volume of composite liquid, such as blood;and at least one sensor associated with each separation cell forgenerating information related to a characteristic of a componentseparated in a separation bag within the separation cell; and a controlunit programmed for receiving information generated by the at least onesensor associated with each separation cell; and for controllingrotation speed in view of information generated by one of the at leastone sensor associated with each of the at least two separation cells.The apparatus is adapted to receive a disposable set of tube-connectedbags. The disposable set preferably comprises a primary bag, initiallycontaining whole blood, fluidly connected to at least one (preferablytwo) component bag for receiving blood components such as plasma orplatelets. A discard bag may also be provided. The disposable set mayfurther comprise a red blood cell collection bag fluidly connected tothe primary bag through a filter.

The apparatus comprises a plurality of valves associated with eachseparation cell. The valves comprise at least one valve adapted tocontrol fluid flow into the at least one component bag, more preferablytwo valves where two component bags are provided, each component valvebeing associated with a component bag. The valves may further comprise adiscard valve for controlling fluid flow of used wash solution into thewash solution discard bag.

The disposable set comprises an asymmetrical junction joining aplurality of tubes of the bag set. The asymmetrical junction can bemounted on the rotor (which carries the valves) in a single orientationonly. Such an action brings the tubes of the disposable set intoproximity with appropriate valves. The bag set can be quickly andunambiguously mounted on the apparatus with less potential for operatorerror.

Further, a well may be provided on a central part of the rotor, adjacentthe valves. The well is adapted to receive a blood component or wasteproduct bag, The bag, being mounted near the axis of rotation of therotor of the apparatus, may be drained into other bags of the set one ormore times. For example, a washing fluid may be used multiple times toreduce the presence of unwanted cell types or other particles in acollected blood component.

The well may be positioned such that the processing bag is located in arelatively high force region of the centrifugal field produced by therotation of the rotor, while the component bags are located in a loweror intermediate force region, and a small bag placed in the well wouldbe in the lowest force region or low force region. Air will tend tocollect in the small bag in the well and a shorter line or tube can beused to connect the small bag to the entire bag assembly. The threeplacement zones aides in simplifying the bag assembly and makes theprocess of loading the bag assembly into the rotor easier.

Other features of the apparatus include a control unit programmed forcausing the rotor to rotate at a sedimentation speed for separating aleast two components in at least two primary or separation bagscontained in the at least two separation cells respectively; causing atleast one valve associated with each separation cell to allow a flow offluid between each separation bag and the component bag connectedthereto; causing the component transferring means to transfer at least aportion of a separated component from each of the at least twoseparation bags into the component bag connected thereto; and causing atleast one valve associated with each separation cell to block a flow offluid between the separation bag within the separation cell and thecomponent bag connected thereto, when the sensor associated with theseparation cell detects the characteristic of a separated component. Thecontrol unit may also slow the rotor, cause hydraulic fluid to be pulledfrom bladders adjacent the primary bags, and open wash valves therebyallowing wash solution to flow into the primary bag. The control unitthen causes additional hydraulic fluid to be withdrawn from thebladders, whereby a free fluid surface is created within the primarybag. The control unit may cause the rotor to oscillate, therebyagitating the residual blood component and wash solution within theprimary bag, and then causes the rotor to rotate at a sedimentationspeed for separating the residual blood component and the wash solution.The control unit causes the wash solution discard valve to open,allowing used wash solution to flow into the wash solution discard bag.The residual blood component may be washed a plurality of times, therebyreducing levels of a cellular component or other components such asprions to a medically acceptable level.

Other features and advantages of the invention will appear from thefollowing description and accompanying drawings, which are to beconsidered exemplary only.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a first set of bags designed forcooperating with a separation apparatus.

FIG. 2 is a schematic view, partly in cross-section along a diametricplane, of a first embodiment of a separation apparatus.

FIG. 3 is a top plan view of the separation apparatus of FIG. 2, showingat least part of a set of bags mounted thereon, showing an asymmetricmanifold.

FIG. 4 is a perspective view of a core and set of bags according to FIG.3.

FIG. 5 is a perspective view of a valve.

FIG. 6 is a perspective view of the valve of FIG. 5, with a housingremoved.

FIG. 7 is a cross sectional view of the valve of FIG. 5, taken alongline 7-7.

FIG. 8 is a plan view of the valve of FIG. 5.

FIG. 9 is a top plan view of an alternative embodiment of a core and atleast part of a set of bags mounted thereon, showing an alternativeasymmetric manifold.

FIG. 10 is a perspective view of a core and set of bags according toFIG. 9.

DESCRIPTION OF EMBODIMENT

For the sake of clarity, the invention will be described with respect toa specific use, namely the separation of whole blood into at least twocomponents, in particular into a plasma component and a red blood cellcomponent, or into a plasma component, a platelet component and a redblood cell component. The discrete volume mentioned hereunder willtypically be the volume of a blood donation. The volume of a blooddonation may vary from one donor to another one (for example, 500 mlplus or minus 10% in the United States). It is also recalled that theproportion of the components of blood usually varies from one donor toanother one. In particular, the donor's hematocrit, which is the ratioof the volume of the red blood cells to the volume of the sample ofwhole blood considered, varies from one person to another. In otherwords, the density of blood may slightly vary for one donor to anotherone. It should be understood however that this specific use is exemplaryonly.

FIG. 1 shows an example of a set 10 of bags adapted to be used for theseparation of a composite liquid (e.g. whole blood) into at least onecomponent (e.g. plasma, platelets, or both) and a second component (e.g.red blood cells). This bag set comprises a flexible primary separationbag 12 and two flexible component bags 14, 16 connected thereto.

When the composite liquid is whole blood, the separation bag 12 has twopurposes, and is successively used as a collection bag and as aseparation bag. It is intended to initially receive a discrete volume ofwhole blood from a donor (usually about 500 ml) and to be used later asa separation chamber in a separation apparatus. The separation bag 12 isflat and generally rectangular. It is made of two sheets of plasticmaterial that are welded together so as to define there between aninterior space having a main rectangular portion connected to atriangular proximal portion. A first tube 18 is connected to a proximalend of the triangular portion, and a second tube 20 and a third tube 22are connected on opposite sides adjacent the first tube 18. The proximalends of the three tubes 18, 20, 22 are embedded between the two sheetsof plastic material so as to be parallel. The separation bag 12 furthercomprises a hole 24 in each of its two proximal corners that areadjacent to the three tubes 18, 20, 22. The holes 24 may be used tosecure the separation bag to a separation cell on a centrifugal bloodseparation apparatus.

The separation bag initially contains a volume of anti-coagulantsolution (typically about 63 ml of a solution of citrate phosphatedextrose for a blood donation of about 450 ml). The first and thirdtubes 18, 22 are fitted at their proximal ends with a breakable stopper26, 28 respectively, blocking liquid flow therethrough. The breakablestopper is sometimes called a “frangible”. The second tube 20 is acollection tube having a needle 30 connected to its distal end. At thebeginning of a blood donation, the needle 30 is inserted in the vein ofa donor and blood flows into the separation bag 12. After a desiredvolume of blood has been collected in the separation bag 12, thecollection tube 20 is sealed and cut, disconnecting the needle from thebag set 10. Alternatively, previously collected blood may be transferredto the separation bag 12 through the collection tube 20, with or withoutthe use of the needle 30.

The first component bag 14 is intended for receiving a plasma component.The bag 14 is flat and substantially rectangular. It is connectedthrough a plasma collection tube 32 and an asymmetric manifold 34 to thefirst tube 18. The second component bag 16 is intended for receiving aplatelet component. The second component bag 16 is also flat andsubstantially rectangular. It is connected through a platelet collectiontube 36 and the asymmetric manifold 34 to the first tube 18. A thirdcomponent bag 38 is intended to receive a red blood cell component(which may be washed), from the primary bag 12. Red blood cells may bedrained through tube 22, which may include a filter 40, into thirdcomponent bag 38. A breakable stopper 42 or frangible in tube 22prevents premature flow of red blood cells into the third component bag38.

A wash solution bag 44, if used, may initially contain wash solutionsuch as saline or a storage solution such as SAGM. Wash solution may betransferred through a wash solution tube 46 and the asymmetricalmanifold 34 by way of the first tube 18 into the primary bag 12 when theprimary bag 12 contains high hematocrit blood cells. “High hematocrit”means a percentage of red blood cell volume to total fluid volume of atleast 80 percent, more preferably 90 percent, and yet more preferably 95percent. After wash solution is mixed with high hematocrit red bloodcells and subsequently separated, used wash solution may be extractedthrough the first tube 18, asymmetrical manifold 34, and discard tube 46into a wash solution discard bag 44. The discard bag 44 could also beused to collect a relatively rare blood component, for example,mesenchymal stem cells or some white cells to reduce filter load.

FIG. 2 shows a first embodiment of an apparatus 60 for simultaneouslyseparating by centrifugation four discrete volumes of a compositeliquid. The apparatus comprises a centrifuge 62 adapted to receive fourof the sets 10 of bags shown in FIG. 1, with the four discrete volumesof a composite liquid contained in the four primary separation bags 12;a component transferring means for transferring at least one separatedcomponent from each separation bag into a component bag connectedthereto. The apparatus 60 may further comprise means for washing aresidual high hematocrit red blood cell component.

The centrifuge 62 comprises a rotor 64 that is supported by a bearingassembly 67 allowing the rotor 64 to rotate around a rotation axis 68.The rotor comprises a cylindrical rotor shaft 70 to which a pulley 72 isconnected; a storage means comprising a central cylindrical container 74for containing component bags, which is connected to the rotor shaft 70at the upper end thereof so that the longitudinal axis of the rotorshaft 70 and the longitudinal axis of the container 74 coincide with therotation axis 68. Four identical separation cells 78 are coupled to thecentral container 74 so as to form a symmetrical arrangement withrespect to the rotation axis 68. The centrifuge further comprises amotor 80 coupled to the rotor by a belt 82 engaged in a groove of thepulley 72 so as to rotate the rotor about the rotation axis 68.

Each separation cell 78 comprises a container 84 having the generalshape of a rectangular parallelepiped. The separation cells 78 aremounted on the central container 74 so that their respective medianlongitudinal axes 86 intersect the rotation axis 68, so that they arelocated substantially at the same distance from the rotation axis 68,and so that the angles between their median longitudinal axes 86 aresubstantially the same (i.e. 90 degrees). The median axes 86 of theseparation cells 78 are inclined downwardly with respect to a planeperpendicular to the rotation axis 68.

Each container 84 comprises a cavity 88 that is so shaped anddimensioned as to loosely accommodate a separation bag 12 full ofliquid, of the type shown in FIG. 1. The cavity 88 (which will bereferred to later also as the “separation compartment”) is defined by abottom wall, which is the farthest to the rotation axis 68, a lower wallthat is the closest to the container 74, an upper wall opposite to thelower wall, and two lateral walls. The cavity 88 comprises a main part,extending from the bottom wall, which has substantially the shape of arectangular parallelepiped with rounded corners and edges, and an upper,or proximal, part, which has substantially the shape of a prism havingconvergent triangular bases. In other words, the upper part of thecavity 88 is defined by two sets of two opposing walls convergingtowards the central median axis 86 of the container 84. One interestingfeature of this design is that it causes a radial dilatation of a thinlayer of a minor component of a composite fluid (e.g. the platelets inwhole blood) after separation by centrifugation, and makes the layermore easily detectable in the upper part of a separation bag. This alsoreduces mixing between component layers by providing a gradual,funnel-like transition into the tube. The two couples of opposite wallsof the upper part of the separation cell 78 converge towards threecylindrical parallel channels (not shown), opening at the top of thecontainer 84, and through which, when a separation bag 12 is set in thecontainer 84, the three tubes 18, 20, 22 extend.

The container 84 also comprises a hinged lateral lid 96, which iscomprised of an upper portion of the external wall of the container 84.The lid 96 is so dimensioned as to allow, when open, an easy loading ofa separation bag 12 full of liquid into the separation cell 78. Thecontainer 84 comprises a locking means (not shown) by which the lid 96can be locked to the remaining part of the container 84. The container84 also comprises a securing or locating means for securing or locatinga separation bag 12 within the separation cell 78. The bag securing orlocating means comprises two pins (not shown) protruding on the internalsurface of the lid 96, close to the top of separation cell 78, and twocorresponding recesses in the upper part of the container 84. The twopins are so spaced apart and dimensioned as to fit into the two holes 24in the upper corners of a separation bag 12.

The separation apparatus further comprises a component transferringmeans for transferring at least one separated component from eachseparation bag into a component bag connected thereto. The componenttransferring means comprises a squeezing system for squeezing theseparation bags 12 within the separation compartments 88 and causing thetransfer of separated components into component bags 14, 16. Thesqueezing system comprises a flexible diaphragm 98 that is secured toeach container 84 so as to define an expandable chamber 100 in thecavity thereof. More specifically, the diaphragm 98 is dimensioned so asto line the bottom wall of the cavity 88 and a large portion of thelower wall of the cavity 88. The squeezing system further comprises aperipheral circular manifold 102 that forms a ring. Each expansionchamber 100 is connected to the manifold 102 by a supply channel 104that extends through the wall of the respective container 84, close tothe bottom thereof. The squeezing system further comprises a hydraulicpumping station 106 for pumping a hydraulic liquid in and out theexpandable chambers 100 within the separation cells 78. The hydraulicliquid is selected so as to have a density slightly higher than thedensity of the densest of the components in the composite liquid to beseparated (e.g. the red blood cells, when the composite liquid isblood). As a result, during centrifugation, the hydraulic liquid withinthe expandable chambers 100, whatever the volume thereof, will generallyremain in the most external part of the separation cells 78. The pumpingstation 106 is connected to the expandable chambers 100, through arotary seal 108, by a duct 110 that extends through the rotor shaft 70,through the bottom and lateral wall of the central container 74, and,radially outwardly where it connects to the manifold 102. The pumpingstation 106 comprises a piston pump having a piston 112 movable in ahydraulic cylinder 114 fluidly connected via the rotary seal or fluidcoupling 108 to the rotor duct 110. The piston 112 is actuated by abrushless DC motor 116 that moves a lead screw 118 linked to a pistonrod. The hydraulic cylinder 114 is also connected to a hydraulic liquidreservoir 120 having an access controlled by two valves 122 a, 122 b forselectively allowing the introduction or the withdrawal of hydraulicliquid into and from a reciprocating hydraulic circuit including thehydraulic cylinder 114, the rotor duct 110 and the expandable hydraulicchambers 100. A pressure gauge 124 is connected to the hydraulic circuitfor measuring the hydraulic pressure therein.

The separation apparatus further comprises four sets of three pinchvalves 128, 130, 132 that are mounted on the rotor around the opening ofthe central container 74. Each set of pinch valves 128, 130, 132 facesone separation cell 78, with which it is associated. The pinch valves128, 130, 132 are designed for selectively blocking or allowing a flowof liquid through a flexible plastic tube, and selectively sealing andcutting a plastic tube. Each pinch valve 128, 130, 132 comprises anelongated cylindrical body 134 and a head 136 having a jaw 138 forming agap that is defined by a stationary lower plate or anvil 140 and the jaw138 movable between a “load” position, an “open” position, and a“closed” position. The gap is so dimensioned that one of the tubes 18,32, 36, 46 of the bag sets shown in FIG. 1 can be snuggly engagedtherein when the jaw is in the open position. The elongated bodycontains a mechanism for moving the jaw and it is connected to a radiofrequency generator that supplies the energy necessary for sealing andcutting a plastic tube. The pinch valves 128, 130, 132 are mountedinside the central container 74, adjacent the interior surface thereof,so that their longitudinal axes are parallel to the rotation axis 68 andtheir heads protrude above the rim of the container 74. The position ofa set of pinch valves 128, 130, 132 with respect to a separation bag 12and the tubes 32, 36, 46 connected thereto when the separation bag 12rests in the separation cell 78 associated with this set of pinch valves128, 130, 132 is shown in dotted lines in FIG. 1. Electric power issupplied to the pinch valves 128, 130, 132 through a slip ring array 66that is mounted around a lower portion of the rotor shaft 70.

Loading a multi-unit blood separator with a plurality of bag sets 10 canbe time-consuming and repetitive. Rapid placement of tubes, such astubes 18, 32, 36 and 46, is enhanced by the ability of the valve jaws inthe “load” position to swing completely clear of a track or grooveadapted to receive a tube. Accurate placement of the tubes is enhancedby the use of the asymmetrical manifold 34. The manifold is comprised ofrelatively rigid plastic and forms a junction for at least three,preferably four, flexible tubes. Connections for the tubes areasymmetrically spaced around the manifold. As shown in FIGS. 1, 3, and4, an embodiment of the asymmetrical manifold 34 comprises an “E”configuration. The “E” configuration comprises a central rigid tube 166with three stubs 168, 171, and 173 connected to tubes 32, 18 and 36,respectively. Diametrically across from the three stubs, a fourth stub175 connects to tube 46 and thence to the auxiliary bag 44. The fourthstub 175 is asymmetrically placed along the tube 166. Because of theasymmetrical shape of the manifold, the manifold can be mounted in ashaped recess on the central core 150 in only one direction. Each of thetubes 18, 32, 36 and 46 of the bag set 10 will consequently be reliablymounted at the proper valve 128, 130, 132 or sensor 158 (describedbelow).

The separation apparatus also comprises a controller 157 including acontrol unit (e.g. a microprocessor) and a memory unit for providing themicroprocessor with information and programmed instructions relative tovarious separation protocols (e.g. a protocol for the separation of aplasma component and a blood cell component, or a protocol for theseparation of a plasma component, a platelet component, and a red bloodcell component) and to the operation of the apparatus in accordance withsuch separation protocols. In particular, the microprocessor isprogrammed for receiving information relative to the centrifugationspeed(s) at which the rotor is to be rotated during the various stagesof a separation process (e.g. stage of component separation, stage of aplasma component expression, stage of suspension of platelets in aplasma fraction, stage of a platelet component expression, etc), andinformation relative to the various transfer flow rates at whichseparated components are to be transferred from the separation bag 12into the component bags 14, 16. The information relative to the varioustransfer flow rates can be expressed, for example, as hydraulic liquidflow rates in the hydraulic circuit, or as rotation speeds of thebrushless DC motor 116 of the hydraulic pumping station 106. Themicroprocessor is further programmed for receiving, directly or throughthe memory, information from the pressure gauge 124 and from four pairsof photocells (described below) and for controlling the centrifuge motor80, the brushless DC motor 116 of the pumping station 106, and the foursets of pinch valves 128, 130, 132 so as to cause the separationapparatus to operate along a selected separation protocol.

A first balancing means initially balances the rotor when the weights ofthe four separation bags 12 contained in the separation cells 78 aredifferent. The first balancing means substantially comprises the samestructural elements as the elements of the component transferring meansdescribed above, namely: four expandable hydraulic chambers 100interconnected by a peripheral circular manifold 102, and a hydraulicliquid pumping station 106 for pumping hydraulic liquid into thehydraulic chambers 100 through a rotor duct 110, which is connected tothe circular manifold 102. Under centrifugation forces, the hydraulicliquid will distribute unevenly in the four separation cells 78depending on the difference in weight of the separation bags 12, andbalance the rotor.

FIG. 3 shows a top plan view of the rotor 64. Four symmetrically spacedseparation cells 78 (each with a lid 96) are shown surrounding a centralcore 150, which contains four sets of valves 128, 130, 132 and whichsupports the asymmetrical manifolds 34 and tubes of the bag sets 10. Thecore 150 is supported in the center of the rotor by a spider structurecomprised of four radial support arms 152. The arms 152 define cavities154 between a separation cell 78 and an adjacent set of valves 128, 130,132 on the central core 150. The component bags 14 and 16 (for plasmaand platelets respectively) and the red blood cell component bag 38,with its associated filter 40, are placed in the cavity 154 when the bagset 10 is loaded into the rotor 64. The collection and separation bag12, which initially contains the collected unit of whole blood, isplaced in the adjacent separation cell 78. The auxiliary bag 44, whichmay be used for temporary fluid storage, waste fluid collection orcollection of a rare or small-volume blood component, is placed in awell 156 close to the axis of rotation 68 (see FIG. 2) of the rotor. Thewell 156 is closer to the axis of rotation than at least some of thevalves associated with a single set 10 of bags. The well 156 may becylindrical or rectangular to accommodate a rectangular bag 44, as shownin FIG. 1. The well is positioned such that the processing or primaryseparation bag 12 is located in a relatively high force region of thecentrifugal field produced by the rotation of the rotor, while thecomponent bags 14, 16 are located in a lower force region, and thesmaller wash solution or discard bag 44 placed in the well would be inthe lowest force region. By reason of bag placement in high,intermediate and low force regions of the centrifugal field, air willtend to collect in the wash bag 44 in the wel 156l. Moreover, a shorterline or tube can be used to connect the small bag to the entire bagassembly. The three placement zones aides in simplifying the bagassembly and makes the process of loading the bag assembly into therotor easier.

FIG. 3 shows an asymmetric manifold 34 having an “E” configuration,which will be explained in greater detail below. For each set of valves,two outer valves 128, 132 are shown in “load” configuration, that is,the jaw of the valve does not extend over an adjacent tube, therebyallowing the manifold 34 and tubes to be installed in their properconfiguration on the central core 150. For each set of valves, an inneror center valve 130 is shown in a position that could be either “open”or “closed”, depending on the vertical position of the valve head andjaw, whereby flow in the adjacent tube is either permitted or impeded,respectively.

A tube sensor 158 is able to detect the presence or absence of liquid inthe tube 18 as well as to detect blood cells in a liquid. Each sensor158 may comprise a photocell including an infrared LED and aphoto-detector. Electric power is supplied to the sensors 158 throughthe slip ring array that is mounted around the lower portion of therotor shaft 70. In the process of separating blood into component parts,fluid components, such as plasma or platelets, are expressed out of theseparation bag 12 in the separation cell 78 into component bags 14, 16in the cavities 154. The sensor 158 may detect the presence of plateletsor red blood cells. In response, the controller 157 may interrupt orchange the processing for the particular set of bags where the newcondition was sensed. Since the process of blood separation proceeds atdifferent rates for different blood units, the volumes and weights offluids in different bags and locations on the rotor will differ. Asecond balancing means 160 balances the rotor when the weights of thecomponents transferred into the component bags 14, 16 in the cavities154 are different. For example, when two blood donations have the samehematocrit and different volumes, the volumes of plasma extracted fromeach donation are different, and the same is true when two blooddonations have the same volume and different hematocrit. The secondbalancing means comprises a balance assembly or ring 160, moreparticularly described in U.S. patent application Ser. No. 11/751,748,filed May 22, 2007, and incorporated herein by reference. The balancingapparatus of the separation apparatus comprises one or two balancingassemblies, each including a series of ponderous satellites or ballsthat can move freely on a specific circular orbit centered on andperpendicular to the axis of rotation of the rotor. The housingcomprises a container for spherical ponderous satellites (balls) 162,which are housed in a cylindrical outer race, in which the ballsslightly engage, and on which they roll, when the rotor rotates. Thebalancing means 160 comprises a plurality of balls. When the balls arein contact with each other, they occupy a sector of the ring of about180 degrees. The balancing means 160 also comprises a damper ordampening fluid or element for providing resistance to the movement ofthe balls.

A valve unit 170 for valves 128, 130 and 132 is shown in FIGS. 5, 6, 7and 8. The valve unit 170 comprises a valve housing 172 that is attachedto a stepper motor 174 at the bottom and a non-conducting valve cover176 at the top. The valve head 136 and jaw 138 protrude through thevalve cover 176. In either the “open” or “closed” positions or if a weldis made, the jaw 138 is centered over a welding anvil 178. A positionsensor 180 on the side of the valve housing 172 senses the verticaldisplacement of a shaft assembly 182 inside the housing and communicatesthat position information to the controller 157. The shaft assembly 182comprises a shaft 184 that engages a spring-loaded coupling 186 at adistal end of the shaft 184, and a valve head 136 at a proximal end ofthe shaft. A combined cam and bearing 188 near the proximal end of theassembly has a guide slot 190 that engages a stationary pin 192. Aspiral section 194 of the slot causes the head 136 and jaw 138 to rotate90 degrees as the shaft 184 is displaced by the stepper motor 174. Astraight section 196 of the slot causes the head 136 and jaw 138 totranslate upward or downward without rotation. As a bearing, thecombined cam and bearing 188 supports the shaft 184, allowing the shaftto translate up and down and to rotate. An O-ring seal 198 preventsfluids from entering the valve unit 170.

The spring-loaded coupling 186 comprises a casing 200 with a sensingsurface 202 in magnetic contact with the position sensor 180 and alongitudinal slot 204 that engages a pin 206 such that the coupling 186can move up and down within the valve housing 172, without rotating. Aspring 208 within the casing 200 and surrounding the shaft 184, pushesagainst an upper end 210 of the casing 200 and against a washer 212 onthe bottom end of the shaft 184. A bearing 213 below the washer allowsthe shaft 184 to rotate. A plunger 214 and joint 216 couple the steppermotor to the coupling 186 and translate the motion of the stepper motorto the coupling 186. As the coupling descends, the shaft 184 pulls head136 down and the combined cam and bearing 188 turns the shaft 184, firstrotating the jaw 138 as it descends and then lowering the jaw withoutrotation until the jaw contacts a tube, a position of the jaw called the“open” position. Further descent of the coupling 186 in response to theaction of the stepper motor squeezes the jaw against the tube until thetube is closed and fluid flow is impeded. This action compresses thespring 208. If radio frequency energy is then directed through the jaw138 and the electrically grounded welding anvil 178, the tube will meltand seal. The spring 208 expands during this process, lowering the jaw138 towards the anvil 178 with a relatively constant pressure whilemaintaining the jaw in contact with the melting tube.

An alternative embodiment of the central core 150′ and asymmetricalmanifold 34′ is shown in FIGS. 9 and 10. In FIG. 10, valves are shown ina raised or “load” position, which allows an asymmetric manifold andtubes associated with a bag set to be quickly and accurately loaded intothe apparatus. The alternative embodiment of the asymmetrical manifold34′ comprises an “F” configuration. The “F” configuration comprises aradial central rigid tube 166′ connected directly to tube 18, which isthe tube connected to the separation or whole blood bag. Three stubs168′, 173′ and 175′ connected to tubes 32′, 36′ and 46′, respectively.The stub 175′ connects to tube 46′ and thence to the auxiliary bag 44.The stub 175′ is asymmetrically placed along the tube 166′ on theopposite side from stubs 168′ and 173′. Once again, because of theasymmetrical shape of the manifold, the manifold can be mounted in ashaped recess on the central core 150′ in only one direction. Each ofthe tubes 18, 32′, 36′ and 46′ of the bag set will consequently bereliably mounted at their proper valves 128′, 130′, 132′ or sensor 158.In this embodiment, all the bags 14, 16, 38, and 44, except theseparation bag 12, are placed in the separation cells 78. This includesthe wash solution/discard bags 44, which, in the previous embodiment,were placed in the centralized wells 156.

It is believed that the valve design described herein facilitatesloading and unloading of blood bags and associated tubing and bag sets.In addition, the asymmetrical junction in the blood bag and tubing setinhibits errors when the bags and tubing sets are loaded into thedevice. Further, the well on a rotor near the axis of rotation, asdescribed above, may be provided for receiving a relatively rare bloodcomponent, such as mesenchymal stem cells (MSC), or for receiving afluid that can be used multiple times, such as a washing solution.

It will be apparent to those skilled in the art that variousmodifications can be made to the apparatus and method described herein.Thus, it should be understood that the invention is not limited to thesubject matter discussed in the specification. Rather, the presentinvention is intended to cover modifications and variations.

1. An apparatus for separating at least two discrete volumes of acomposite liquid into at least a first component and a second componentcomprising a centrifuge rotor adapted to rotate about a rotation axis,at least one separation cell, adapted to receive a separation bag of aset of fluidly interconnected bags, said set comprising at least saidseparation bag containing a volume of composite liquid, and at least onecomponent bag, a cavity adapted to receive at least said component bag,a plurality of valves, the valves being adapted to control fluid flowbetween parts of the set of interconnected bags, at least one of saidvalves comprising a jaw mounted on a shaft, said jaw being adapted tomove from a load position allowing at least one tube to be placedadjacent said valve to an open position over said tube and from saidopen position to a closed position constricting fluid flow through saidtube, and a controller electrically connected to said valves, saidcontroller controlling the status of said valves, wherein said valvesfurther comprise a cam mounted on said shaft, said cam guiding said jawin a translating and rotating motion from said load position to saidopen position and in a translating motion from said load position tosaid closed position.
 2. The apparatus according to claim 1, whereinsaid valves are placed to receive an asymmetrical manifold in a uniqueorientation.
 3. The apparatus according to claim 2 wherein said rotorfurther comprises a recess shaped to receive said manifold in a uniqueorientation.
 4. The apparatus according to claim 3 wherein said recessis adapted to receive at least three tubes which are coupled to saidmanifold.
 5. The apparatus of claim 3 wherein said recess has an “E”shape.
 6. The apparatus of claim 3 wherein said recess has an “F” shape.7. The apparatus according to claim 1, wherein said jaw is adapted toapply radio frequency energy to an adjacent tube to seal said tube, andfurther comprising a spring coupled to said shaft and being adapted tomaintain said jaw in contact with said tube as said tube is sealed. 8.The apparatus of claim 7, wherein said valve further comprises a cammounted on said shaft, said cam guiding said jaw in a translating androtating motion from said load position to said open position and in atranslating motion from said load position to said closed position. 9.The apparatus according to claim 8, wherein said valves are placed toreceive an asymmetrical manifold in a unique orientation.
 10. Theapparatus according to claim 9 wherein said rotor further comprises arecess shaped to receive said manifold in a unique orientation.
 11. Theapparatus according to claim 10 wherein said recess is adapted toreceive at least three tubes which are coupled to said manifold.
 12. Theapparatus of claim 10 wherein said recess has an “E” shape.
 13. Theapparatus of claim 10 wherein said recess has an “F” shape.